Seafrost engine driven compressor

[Richard Kollmann]

Originally Posted by Jill on Maya

This looks to be appropriate thread to ask whether its true that an engine driven fridge compressor (e.g. our Sanden SD5 or SD7 - I can't remember which it is) ideally should be run at least once a month to keep the seals lubricated? A fridge technician recently suggested that leaving the compressor idle (not used) for months at a time shortens the life of the compressor.

There Are different Btu outputs of each of the Sanden compressors The SB 505 is the smallest requiring a different mounting bracket. The most common model for engine driven refrigeration was the SD508. The SD seven normally had a single belt drive clutch. None of the original Sanden compressors are manufactured today.

The Sanden compressor has a second generation shaft seal and clutch loading was not involved with seal leaks as with first generation compressors. The newer seal is a spring loaded carbon disc against a stainless plate. The first rubber seal would ware out but the newer seal retains refrigerant pressure inside compressor as long as there is oil between carbon seal and stainless plate.
To answer your question how often will this second generation seal need to be refreshed with surface oil? Some times six months but manufacture recommends rotating compressor more frequently. Originally these compressors were designed for auto AC systems where engine ran at least every two weeks. The other advantage of carbon seal over the old rubber seal is it repairs itself every time compressor runs. Is it possible over the life of your enging drive refrigeration additional refrigerant will be needed ? Maybe.
Did your tech person have to add refrigerant and said loss was do to a leak he could not find?, You decide.

[Coolerking]

Indeed, I ran a number of racing yachts a few decades back and they all had the 505 sandens in them, they ran 2 boxes, with large eutectic plates in them, they were great as long as the mount was tied to the motor and not the boat as the pounding and flying off waves would chuck the belts off the pulley...

[Finalee]

I just brought a York system back to life. Works great! Question : Is the York compressor noisier than the Sanden?

[Richard Kollmann]

Originally Posted by Finalee

I just brought a York system back to life. Works great! Question : Is the York compressor noisier than the Sanden?

Yes the York two cylinder is noisier than the five cylinder Sanden actual flow compressor because of belt resident frequency vibration.